Papers by Keyword: Barium

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Authors: M.A. Platonov, I.S. Sulimova, Irina D. Rozhikhina
Abstract: The paper considers carbon, silicon and aluminum reduction of barium and strontium from natural materials by thermodynamic modeling in conditions of out-of-furnace steel treatment. X-rays phase and differential thermal methods of analysis were applied to investigate the samples of natural barium and strontium containing material. A process flowsheet of steel treatment by barium-strontium modifier in induction furnace was developed on the basis of carried out research.
Authors: György Vida, Ildikó Beck, V. Katalin Josepovits, Miklós Győr
Abstract: In the present paper the secondary emission and work function of W covered with different thickness Ba layers are compared. The secondary emission and work function were measured by Work Function Spectroscopy (WFS). It is clearly pointed out that the thin Ba coating causes the the enhancement of electron induced secondary electron emission. In high pressure discharge lamps high secondary emission and high thermionic current are required for reliable operating conditions, i.e., for reaching the nominal burning voltage and current etc. The results prove that the Ba spreading on the W surface from an alkali earth tungstate material is advantageous for lowering the work function and, simultaneously, for increasing the secondary emission yield.
Authors: P.I. Paulin Filho, R.R. Corrêa
Authors: Kosuke Muraoka, Seiji Ishikawa, Hiroshi Sezaki, Tomonori Maeda, Shinichiro Kuroki
Abstract: A correlation between field effect mobility and an accumulation conductance has been investigated at 4H-SiC MOS interface with barium. 4H-SiC n-channel MOSFETs and n-type MOS capacitors were fabricated with a barium-introduced SiO2 and a conventional dry SiO2. The field effect mobility was enhanced by introducing the barium-introduced SiO2. It is found that there is a linear correlation between the mobility and the accumulation conductance. The MOS interface of the barium-introduced SiO2 had a lower interface state density of 2×1011 cm-2eV-1 than that of the conventional dry SiO2.
Authors: Hajo Dieringa, Daniela Zander, Mark A. Gibson
Abstract: The development of creep resistant high pressure die casting (HPDC) alloys is one of the main focuses in magnesium research. Alloying elements like rare earths, calcium, strontium or scandium added to the necessary aluminium for die casting have already been introduced. Newly developed barium containing magnesium alloys with three levels of alloying additions were processed via HPDC and their compression creep response at 200 °C was evaluated. DieMag633 (Mg-6Al-3Ba-3Ca) displays the best creep resistance followed by DieMag422 (Mg-4Al-2Ba-2Ca) and then DieMag211 (Mg-2Al-1Ba-1Ca). Stress exponents from tests at different applied stresses were calculated. The creep tests were also accompanied by microstructural investigations and mechanical property evaluation.
Authors: Kosuke Muraoka, Hiroshi Sezaki, Seiji Ishikawa, Tomonori Maeda, Tadashi Sato, Takamaro Kikkawa, Shinichiro Kuroki
Abstract: Enhanced-oxidation of 4H-SiC and interface modification with BaO2 was investigated. The enhanced oxidation of 4H-SiC was drastically dependent on pre-deposited BaO2 thickness. At the oxidation time of 300 min, oxide thicknesses for BaO2 of 2.8 nm and 7.8 nm were 91.8 nm and 26.2 nm, respectively. The physical state of Ba in the oxide was investigated by XPS and 2D-GIXD. At thick BaO2 with a thickness of over 6.4 nm, bridged oxygen and non-bridged oxygen were observed in O1s state. This results shows barium silicate was formed in SiO2 at BaO2 thickness of over 6.4 nm.
Authors: Ding Wei, Xin Wang, Z K Feng, R Z Gong
Abstract: Sendust soft magnetic composites coated by a thin Ba-B-P-O system insulating layer were produced; SEM spectroscopy and Energy dispersive X-ray analysis spectroscopy confirmed that thin layers of Ba-B-P-O system covered the alloy powders. The influence of various compaction pressures on composites permeability, DC properties and total loss was investigated. The Fe-Si-Al magnetic powder core with compaction pressure of 1932MPa, annealing temperature of 953K with a permeability of 94, a total loss of 108 mW/cm3.
Authors: Tomo Kobayashi, Yuji Noguchi, Masaru Miyayama
Abstract: Intergrowth-structured Bi4Ti3O12-BaBi4Ti4O15 (BiT-BBTi) single crystals were grown by a self-flux method, and the crystal structure and polarization properties were investigated. Transmission electron microscope observations and X-ray diffraction analysis presented direct evidence of the intergrowth structure composed of the alternate stacking of BiT and BBTi layers. The BiT-BBTi crystals showed a giant spontaneous polarization (Ps) along the a axis of 52 μC/cm2, which was larger than those of the crystals of BiT (46 μC/cm2) and BBTi (16 μC/cm2). The large Ps of the BiT-BBTi crystals is suggested to originate from the ferroelectric displacements of the Bi of Bi2O2 layers as well as from the Bi substitution for Ba induced by compositional deviation. It was found that the polarization properties of the BiT-BBTi crystals depend strongly on the composition.
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